A new self-gated system with 4 detection channels and all signal processing has been delivered and performs to specifications, eliminating the problem of calibration stability. Calibration stability is now 1%. New fibers are being developed by NRL that will be more uniform in dose response and will be based on a 100 micron optical fiber rather than the current 400 micron model. The resulting system will undergo validation as a radiation dosimeter and will be employed for non-routine clinical and research measurements involving small field and micro-field dosimetry for both megavoltage and kilovoltage x-ray and electron beams Additionally, modification to the software will permit operation of the device in continuous acquisition as well as pulsed mode. This will permit use of the device for dosimetry with lower energy x-ray energies (orthovoltage x-rays and most brachytherapy sources). This is important for the measurement of very small field size dose distributions and output factors associated with the newly acquired small animal imaging irradiator.